This invention relates to a device and methodology for characterizing superconductive materials. Specifically, the invention is directed to a device and methodology for determining superconductive transitions without the need for contact with the material and suitable for use with samples that are in the form of powder, thin films, ceramics or single crystals.
The recent discovery of superconductivity at relatively high temperature in Y-Ba-Cu-O materials has started an intensive worldwide search for new superconducting materials. Numerous materials are synthesized daily and tested for superconductivity in many laboratories throughout the world. In order to expedite this effort, a rapid and reliable method is required for eliminating non-promising materials. The most obvious means of determining superconductivity is by an electrical resistance test. However, such a test requires electrical contact with the materials which is difficult, especially if the material is in powdered form.
Commonly, a non-contact magnetic test of flux exclusion or flux expulsion (the Meissner effect) is used to determine if a material is a superconductor. Unlike the electrical resistivity measurement, the magnetic test does not require contact with the materials and can be performed on materials in the powdered state. However with respect to multiphase materials, i.e. materials that exhibit several superconducting transitions, the magnetic testing does not clearly reveal the presence of all the transitions. The present invention provides a inexpensive non-contact device for detecting such superconducting transitions.